1. Field of the Invention
The present technology relates to the field of pesticidal protection, particularly activity in soil environments that need to be protected from or cleansed of pests that might be of concern. These treatments include delivery of active ingredients and delayed activity ingredients.
2. Background of the Art
The control of arthropod pests is extremely important in achieving high crop efficiency. Arthropod damage to growing and stored agronomic crops can cause significant reduction in productivity and thereby result in increased costs to the consumer. The control of arthropod pests in forestry, greenhouse crops, ornamentals, nursery crops, stored food and fiber products, livestock, household, and public and animal health is also important. Many products are commercially available for these purposes, but the need continues for new compounds that are more effective, less costly, less toxic, environmentally safer or have different modes of action.
Nematodes (derived from the Greek word for thread) are active, flexible, elongate, organisms that live on moist surfaces or in liquid environments, including films of water within soil and moist tissues within other organisms. While only 20,000 species of nematode have been identified, it is estimated that 40,000 to 10 million actually exist. Some species of nematodes have evolved as very successful parasites of both plants and animals and are responsible for significant economic losses in agriculture and livestock and for morbidity and mortality in humans (Whitehead (1998) Plant Nematode Control. CAB International, New York.).
Nematode parasites of plants can inhabit all parts of plants, including roots, developing flower buds, leaves, and stems. Plant parasites are classified on the basis of their feeding habits into the broad categories, migratory ectoparasites, migratory endoparasites, and sedentary endoparasites. Sedentary endoparasites, which include the root knot nematodes (Meloidogyne) and cyst nematodes (Globodera and Heterodera) induce feeding sites and establish long-term infections within roots that are often very damaging to crops (Whitehead, supra). It is estimated that parasitic nematodes cost the horticulture and agriculture industries in excess of $78 billion worldwide a year, based on an estimated average 12% annual loss spread across all major crops. Continuing population growth, famines, and environmental degradation have heightened concern for the sustainability of agriculture, and new government regulations may prevent or severely restrict the use of many available agricultural anthelmintic agents.
The situation is particularly dire for high value crops such as strawberries and tomatoes where chemicals have been used extensively to control of soil pests. The soil fumigant methyl bromide has been used effectively to reduce nematode infestations in a variety of these specialty crops. It is however regulated under the U.N. Montreal Protocol as an ozone-depleting substance and is scheduled for elimination in 2005 in the US (Carter (2001) California Agriculture, 55(3):2).
Fatty acids are a class of natural compounds that have been investigated as alternatives to the toxic, non-specific organophosphate, carbamate and fumigant pesticides (Stadler et al. (1994) Planta Medica 60(2):128-132; U.S. Pat. Nos. 5,192,546; 5,346,698; 5,674,897; 5,698,592; 6,124,359). It has been suggested that fatty acids derive their pesticidal effects by adversely interfering with the nematode cuticle or hypodermis via a detergent (solubilization) effect, or through direct interaction of the fatty acids and the lipophilic regions of target plasma membranes. In view of this general mode of action it is not surprising that fatty acids are used in a variety of pesticidal applications including as herbicides (e.g., SCYTHE by Dow Agrosciences is the C9 saturated fatty acid pelargonic acid), as bacteriacides and fungicides (U.S. Pat. Nos. 4,771,571; 5,246,716) and as insecticides (e.g., SAFER INSECTICIDAL SOAP by Safer, Inc.).
There remains an urgent need to develop environmentally safe, target-specific ways of controlling plant parasitic nematodes. In the specialty crop markets, economic hardship resulting from nematode infestation is highest in strawberries, bananas, and other high value vegetables and fruits. In the high-acreage crop markets, nematode damage is greatest in soybeans and cotton. There are however, dozens of additional crops that suffer from nematode infestation including potato, pepper, onion, citrus, coffee, sugarcane, greenhouse ornamentals and golf course turf grasses.
Nematode parasites of vertebrates (e.g., humans, livestock and companion animals) include gut roundworms, hookworms, pinworms, whipworms, and filarial worms. They can be transmitted in a variety of ways, including by water contamination, skin penetration, biting insects, or by ingestion of contaminated food.
In domesticated animals, nematode control or “de-worming” is essential to the economic viability of livestock producers and is a necessary part of veterinary care of companion animals. Parasitic nematodes cause mortality in animals (e.g., heartworm in dogs and cats) and morbidity as a result of the parasites' inhibiting the ability of the infected animal to absorb nutrients. The parasite-induced nutrient deficiency results in diseased livestock and companion animals (i.e., pets), as well as in stunted growth. For instance, in cattle and dairy herds, a single untreated infection with the brown stomach worm can permanently stunt an animal's ability to effectively convert feed into muscle mass or milk.
Human infections by nematodes result in significant mortality and morbidity, especially in tropical regions of Africa, Asia, and the Americas. The World Health Organization estimates 2.9 billion people are infected with parasitic nematodes. While mortality is rare in proportion to total infections (180,000 deaths annually), morbidity is tremendous and rivals tuberculosis and malaria in disability adjusted life year measurements. Examples of human parasitic nematodes include hookworm, filarial worms, and pinworms. Hookworm is the major cause of anemia in millions of children, resulting in growth retardation and impaired cognitive development. Filarial worm species invade the lymphatics, resulting in permanently swollen and deformed limbs (elephantiasis) and invade the eyes causing African Riverblindness. Ascaris lumbricoides, the large gut roundworm infects more than one billion people worldwide and causes malnutrition and obstructive bowl disease.
PCT application PCT/US01/10982, filed 4 Apr. 2001 and published as WO 01/74161 incorporated herein by reference and U.S. Pat. No. 7,019,036 describes pesticidal complexes that are particularly effective with regard to nematodes and penetrants that can be used for various purposes, including as components of the pesticidal compositions. The penetrant surfactant composition consists essentially of at least one linear alcohol of 7 12C which is polyalkoxylated, at least one microemulsion-enhancing component and at least anionic detergent. This penetrant composition can be used in combination with the nematocidal or pesticidal components in agriculture as well as in alternative uses such as topical formulations for pharmaceutical or veterinary use. The pesticidal compositions themselves contain, in addition to the components of the penetrant either a lipase associated with at least one C.sub.16 C.sub.20 monounsaturated fatty acid or ester (including vegetable oils) or a saccharide esterified to at least one monounsaturated C.sub.16 C.sub.20 fatty acid. These compositions, because they contain penetrants which may not be recognized as safe as they actually are, require approval from the Environmental Protection Agency in the United States in order to be sold. In addition, the above-mentioned lipase may be derived from a fungal culture, and the complexities and uncertainties of the components of such cultures prevents their being recognized as safe. It would be desirable to formulate pesticides which are composed entirely of recognized “safe” ingredients that are environmentally friendly. If desired, of course, the compositions could be mixed with penetrants such as those described in WO 01/74161 when they are applied to the soil. This publication also describes methods to use nematacides and pesticides that are applicable to the nematacides and pesticides of the invention.
U.S. Pat. No. 6,875,727 describes a method of controlling pests with macrolide compounds; more specifically A) a method of controlling pests in and on transgenic crops of useful plants, such as, for example, in crops of maize, cereals, soya beans, tomatoes, cotton, potatoes, rice and mustard, with a macrolide compound, characterized in that a pesticidal composition comprising a macrolide compound in free form or in agrochemically useful salt form and at least one auxiliary is applied to the pests or their environment, in particular to the crop plant itself; B) A method of protecting plant propagation material and plant organs formed at a later point in time from attack by pests, characterized in that a pesticide comprising, as pesticidally active compound, at least one macrolide compound as active ingredient and at least one auxiliary in close spatial proximity to, or spatially together with, planting or applying the propagation material is employed to the site of planting or sowing; C) a method of controlling wood pests and molluscs with a macrolide compound, wherein a pesticidally active amount of a pesticide comprising, as pesticidally active compound, at least one macrolide, in free form or agrochemically utilizable salt form, as active ingredient and at least one auxiliary is applied to the pests or their environment; the corresponding use of these compounds, corresponding pesticides whose active ingredient is selected from amongst these compounds, a method for the preparation and the use of these compositions, and plant propagation material which is protected in this manner from attack by pests.
U.S. Pat. No. 5,997,945 describes adherent starch particles that may be used to carry microbicides. In PCT Int. Appl. WO 85/04074, Flashinski et al. disclose two methods of preparing a starch gel matrix containing an insecticide. The insecticide is either coextruded with a dilute, aqueous dispersion of starch, or the starch is first partially cooked in an extruder prior to cold-blending with the insecticide. In either case, the product is recovered and used as an aqueous gel.
In U.S. Pat. No. 4,230,687, Sair et al. disclose the application of shearing stress, vigorous mechanical working, and heat to distribute an active agent into an enveloping matrix of chemically modified starches, gums, and proteins in the presence of a limited quantity of water. Proteins are used for slow-release matrices; modified starches are used for rapid release.
Similarly, in U.S. Pat. No. 3,922,354, Galuzzi et al. disclose the use of high-shear mixing to incorporate active agents into low-water, high-solid matrices prepared from partially gelatinized unmodified starches. Additives such as modified dextrins, mixtures of mono and diglycerides, toasted cereal solids, and coloring agents are used to control the release of active agents.
In U.S. Pat. No. 3,666,557, Jensen et al. disclose a method of using low-fat starchy materials to microencapsulate individual beadlets of sensitive materials such as vitamins and vegetable oils. Starches are prepared for encapsulation by heating at 88° C. for 30 minutes followed by passage through a homogenizer to effect disruption of granules without degradation of molecules.